Multiple cyclones may threaten a rain-hit region already bracing for another deluge after enduring flooding and a major road closure.
Heavy rainfall battered north Queensland overnight, with two people rescued from floodwaters after some areas received more than 300mm.
The Bruce Highway - the state's major arterial road - was closed in the north after significant falls caused by a tropical low off the coast near Cairns.
More rain and possible flooding is expected up to the weekend with the Coral Sea tropical low a chance of forming a cyclone as early as Thursday.
Another tropical low in the Gulf of Carpentaria could also develop into a cyclone by Sunday.
The Coral Sea low was a five per cent chance of forming into a tropical cyclone on Thursday, increasing to 25 per cent by the weekend, according to forecasters.
"The ocean temperature of the Coral Sea is about 28 to 30 degrees, so ideal conditions for further development and whether or not it can sustain that development will be the real watch point," the Bureau of Meteorology's Jonathan How told AAP.
The bureau is also keeping an eye on the low in the Gulf.
"The low-pressure systems, both in the Gulf of Carpentaria and in the Coral Sea ... have the potential to develop into a tropical cyclone with a moderate chance from Sunday," meteorologist Sarah Scully said.
"But regardless of whether these systems do ... this low-pressure system (in the Coral Sea) has the potential to dump an enormous amount of rainfall."
Another tropical low in the Coral Sea was set to develop near Vanuatu and form a cyclone by the weekend but it was unlikely to impact the Australian coast.
The Queensland premier reassured those who may be in the path of potential cyclones.
"We are on active alert, so are the local communities, and we'll do everything possible to make sure that those communities are prepared," David Crisafulli said of the cyclone threat.
Cyclones may also form off Western Australia this week.
A low could develop north of the Kimberley coast by the weekend and was a low risk of developing into a tropical cyclone from Saturday.
Another low may form northwest of WA later in the week and pass south of the Cocos (Keeling) Islands.
"There is a low chance of it developing into a tropical cyclone from Saturday, increasing to moderate next Monday," the bureau said.
Residents have been urged to keep an eye on the latest updates and warnings after far north Queensland's deluge, with emergency alerts to be sent via text.
About 316mm was recorded north of Innisfail in 24 hours by Wednesday morning, with Cairns Racecourse receiving 216mm and Gordonvale 213mm.
Heavy rainfall led to flash flooding with two people rescued at Gordonvale.
A severe weather warning which could lead to more flash flooding remains for the North Tropical Coast and Tablelands forecast district.
A number of flood watches have been issued across the region with warnings current for the Tully and Mulgrave Rivers.
